There are three kinds of bicycle carriers in the market:                a. Roof mounted        b. Rear door mounted        c. Hitch mounted        
The roof mounted type are the most popular, and provide a very good solution for mounting the bikes to the carrier, as they secure the bicycle by three points, one on each wheel and a third one on the bicycle frame. Its major drawback is the height needed to lift the bicycle when loading. Another problem is a lack of option to simply disassemble the carrier, for car washing or for preventing wind turbulence around the roof rack.
The rear door mounted carriers are fixed to the rear door or trunk door with cables or straps. This type can be adapted easily to different kinds of cars. The carriers are compact, and can be disassembled and left at the car trunk, leaving enough room for other stuff.
They have three main disadvantages: the first is the difficulty to secure the bicycle to the carrier; the second is poor attachment of the bikes to the carrier (which might cause scratching); and thirdly—the height needed to load the bicycle (above shoulder height) in most of car models. In these carriers, there is no option to load other freight other than bicycle.
The hitch bar carriers are the most convenient to transport bikes or other freights. They can be secured tightly, in a similar way as the roof mounted carriers and even better. Their main advantage is that there is no need to lift them above the shoulder. They are very easy to assemble and disassemble, and are compatible for different types of freight. Their main disadvantage is the need to install the hitch bar on the car body, which is an expensive procedure, and cannot be transferred from car to car. Accordingly these carriers are not popular for private cars.
The present invention includes all the advantages of the hitch type carrier mentioned above, but does not require installation of the hitch itself. This makes it cheaper, easy to assemble and disassemble, and thereby compatible to transfer from car to car.